Hello @Susana302 ,
hope you are well.
My best bet is that they maybe did not register the request entirely and it was overlooked or they saw and chose to ignore it.
I would suggest you escalate this to Airbnb- and provide as much information and proof as to back up your claim- this would make it easier for them to side with you.
Alongside I would write a kind but clear email to the guest explaining the situation again and the need to escalate it to Airbnb. Most would quickly react to this and action it accordingly, especially if they have no leg to stand on. Keep all communication on the Airbnb app and good luck!
Hope this answered your question and have a great day!
Yadira 🙂